1. Field of the Invention
The present invention relates to an opening-closing device suitable for use particularly in opening and closing Western style toilet seat and seat cover.
2. Description of the Related Art
As this type of opening-closing device, a pair of opening-closing devices having a rotating shaft fitted with a rotation control means have been known. These devices are mounted at a specific spacing at the rear upper end of the toilet bowl in order to prevent abrupt drop of the seat and seat cover. One of the opening-closing devices is for the toilet seat, while the other is for the seat cover. In the prior art opening-closing device, a mounting section of the seat is secured on one mounting shaft portion of the rotating shaft and at the same time the mounting section of the seat cover is rotatably supported. Also on the mounting shaft portion of the other rotating shaft, the other mounting section of the seat is rotatably supported and the mounting section of the seat cover is secured, so that either opening-closing device will operate when either the seat or the seat cover is opened or closed.
In the prior art opening-closing device, the mounting shaft portion of the rotating shaft to be coupled to the mounting section of the seat and the seat cover and the mounting pin of the seat and seat cover to be inserted into an irregular mounting hole provided axially in the rotating shaft are irregular shafts of approximately elliptical section which are formed by cutting off their both sides. The irregular shaft is fixed in one irregular hole of the seat and seat cover mounting section, and inserted into a round hole. Therefore there arises such a disadvantage that the seat and seat cover are likely to vibrate more or less when opened or closed, and since the opening-closing device with the rotation control means acts only on one side of the seat and seat cover mounting section.